I am broadly interested in the diversity of marine life: where it comes from, what keeps it ticking, and how diverse living organisms create the natural products and services that human lives and economies depend on.Understanding these issues involves answering questions about evolution like: How and why do new species arise? And questions about basic ecology such as: What factors determine whether and which species end up living together? How do the types of species present influence how ecosystems work, and the products and services they provide to us? Finally and most importantly, how can understanding these complex interactions inform our ability to live sustainably on a finite planet?

We address such questions by integrating approaches from experimental ecology, phylogenetic comparative biology, and behavioral ecology, with good doses of taxonomy and quantitative modeling mixed in. Most of our research focuses on how marine animals use resources and interact, and the consequences of those interactions for populations, communities, and ecosystems. Some long-running research themes include
(1) studies of how biodiversity, food-web structure, and environmental change interact to affect ecosystem processes in seagrass beds,
(2) how taxonomic and functional diversity influence ecosystem structure and function more broadly in the living world, and
(3) systematic, ecological, and behavioral studies of the evolutionary radiation of symbiotic shrimp, including the only known marine eusocial animals, on Caribbean reefs.

A more recent focus is synthetic marine biodiversity science. Duffy joined the Smithsonian in September 2013 to lead the Tennenbaum Marine Observatories, the first long-term, global program to understand biodiversity in the coastal oceans and how it’s changing. In 2013 he received funding for the second generation of the Zostera Experimental Network, a global collaboration working to understand how biodiversity and environment interact to make seagrass ecosystems work, and how they are changing, on scales from plots to planet.